This invention relates to athletic shoes with cleated outer soles and more particularly to such athletic shoes for wear on synthetic or artificial turf of the kind that is surfaced with tufts of fibers that are locked to the surface of the turf and are generally upstanding from that surface in simulation of grass.
The introduction of synthetic or artificial turf such as Astroturf as a playing surface for football, soccer, baseball and other sports has been a benefit to the play of such games, but is clearly not the same and has different properties than a natural grass field that is properly conditioned with moist soil. On natural grass fields, the well-known conical cleat used on football and soccer shoes penetrates the grass surface into the soil and the lateral forces exerted on the hole in the soil caused by the penetrating cleat are contained; and, as a result, the player propells himself in the direction he intends without slipping. The resistance of slightly moist soil bound together by the grass roots and the blades of grass projecting upwards a few inches provides a sure footing for the player wearing such conical cleats, because the cleats can penetrate the blades of grass into the roots and soil. If the grass playing field is excessively wet, the soil becomes muddy and the lateral resistance of the soil to the penetrating cleat is not sufficient and the player slips. On the other hand, if the soil is excessively dry, it becomes hard and the cleat cannot penetrate and traction is poor.
Such conical cleats suitable on grass are not suitable on artificial turf, because the artificial turf cannot be penetrated. The cleated outer soles that have been developed in the past for play on artificial turf that has tufts of fibers on the surface as a simulation of grass, are usually molded as an integral part of the shoe sole. These include soles with many small conical cleats, each usually smaller than the cleats used on grass. The arrangements of the small conical cleats on the sole vary and some even offer soles with cleats of different sizes. The acceptance of any specific design depends largely on the opinion of the players. Generally, these cleated outer soles are adequate on a dry artifical turf field, but they are not satisfactory when the field is wet. Other cleat geometries such as square, triangular, star, etc. have the same problem on a wet field, in varying degrees.
Since the cleats of athletic shoes do not penetrate the surface of the artificial turf, traction depends upon the friction between the end of the cleat and the tufts of fibers on the surface. When the fibers are wet, they are, in effect, lubricated and the end of the cleat rides on the film of water on the individual fibers and so the cleat slips off. It is an object of the present invention to provide a cleat design and an arrangement of cleats on the outer sole of an athletic shoe that affords greater traction to the wearer on an artificial turf surface of tufted fibers even when the fibers are wet.
It is another object to provide an improved cleated outer sole for an athletic shoe that enables the wearer to have the necessary traction with a tufted fiber artificial turf when the wearer intentionally accellerates in any direction in normal athletic activity.
It is another object to provide such an outer sole that has substantially less traction with the turf when the wearer's foot is so positioned that high traction would be likely to result in injury.
It is another object to provide an improved cleated outer sole for a football shoe for use on artificial turf having tufted fibers on the surface thereof.
It is another object to provide an improved cleated outer sole for a baseball shoe for use on artificial turf having tufted fibers on the surface thereof.
It is another object to provide an improved cleated outer sole for a shoe for any running sport for use on artificial turf having tufted fibers on the surface thereof.